Abstract
In a manipulation system that executes assembly tasks, contact-state recognition or contact-state-transition detection are important functions. These functions should be modularized as a motion monitoring and evaluation (MME) module. This paper mainly presents a real-time detection method of contact-state-transition with high reliability, and the implementation of the method into the MME module. In the detection algorithm, features which fluctuate abruptly when the contact-state-transition occur are selected according to the motion pattern. In the detection algorithm, the differential of the feature locus is monitored and the transition region is distinguished from the stable region. Then, to confirm whether state-transition really occur in the region, the duration of the region and the feature deviation are counted. Using this method, contact-state-transition is detected with only 40 [msec] delay. An experimental manipulation system, in which motion control and MME modules are independently executed, is developed using transputers and the 6 D.O.F direct drive manipulator ETA 3. In the experiment, six patterns of motion, in which different types of transition occur, are selected. The experimental results show that contact-state-transition is accurately detected and motion commands can be quickly switched using detected transition information.
